I know this hasn't been an easy process for you, @Ksr3.
I appreciate you checking your merchant account settings to get around the issue. I'm here to help you point in the right direction for support.
To address this issue right away, I recommend contacting our Technical Support Team since the Community is a public forum and we'll need to collect some personal information to pull up your account.
From there, they'll perform a screen-sharing session to do further investigation and discuss in great detail the reasons why the transactions are posted multiple times. Please click on this article to view their support hours and follow the steps or get their number under the QuickBooks Payments section: Contact Payments Support.
I’m adding an article to help with your future tasks. It contains topics that answer common questions about the Payments feature. This resource will guide you on how to check the funding status, fix card reader issues, payments processing, etc: QuickBooks Payments FAQ.
You're always welcome to get back to me if you have any other follow-up questions about managing your payment transactions in QuickBooks. I'd be happy to help. Keep safe!